A Solar Furnace

Learn What It Is, How It Functions And How It Can Be Used

Today's technology might make solar furnace one of three leading options for home furnaces in the near future for anyone who wants to move away from traditional gas or fossil fuel options. The other two are solar panels and geothermal heating systems. This article will explain what is it and why we call it a leading future candidates for home furnace.

Solar Furnaces Explained

How does it work?

Solar furnaces work basically by focusing the sun's rays on its special reflector. Remember when you used a magnifying glass to set a paper on fire when you were a child? This is the same principle!

The reflector can be a curved mirror or a number of curb mirrors placed in such a way that the suns rays are concentrated on a focal point of the reflector. Thereby incredibly high temperatures can be produced. This heat can be used to melt metal, produce hydrogen fuel and generate electricity etc.

The principle of operation is quite simple. Take two mirrors, point them at a focus, and the intensity of sunlight in that focus will increase by around threefold. This is because, instead of only getting light from the sun, the focus gets light from the sun and two mirrors. Make that ten mirrors, and you start to get levels of heat that are useful for applications like cooking food.

Solar furnace is a passive solar technique and requires very little conventional electricity to operate. It is simply a way to channel the sunlight to one place and then storing it for future use. The actual storing as well as aligning the mirrors may however require some amount of electricity.

A Solar Furnace vs A Solar Collector?

Well, a solar furnace is simply a type of solar collector. Solar collectors are classified by the USA Energy Information Administration as low-, medium- or high-temperature collectors. Solar furnaces, using mirrors or lenses to concentrate the sunlight, are high-temperature solar collectors. These are often used to produce electricity.

Low temperature collectors are for example flat plates generally used to heat swimming pools. Medium-temperature collectors are also usually flat plates but are used for heating water or air for residential and commercial use.

What are they used for?

Solar furnaces are primarily used to generate heat or steam to make electricity and for industrial use. Steam created by solar furnaces can be used to run generators and industrial equipment. One of the most famous industrial examples is the construction built in France in Odeillo already in 1970.

A small solar furnace may be used to cook food without consuming firewood and there have been experiments in developing countries with this.

An option for home heating?

The technical solar gadget to the right is an example of a small solar furnace. Maybe not a very useful item, unless you want to teach your children about the power of the sun. You can read more about it and buy it here.

But how about usage that actually makes a difference for your heating or electricity bill?

A solar furnace really is the most efficient catcher of solar energy to produce electricity. As of yet, they are however not used extensively in residential solar power systems. But that might change...

The American company GoSolarUSA announced in mid 2010 that they had acquired the exclusive rights to the patent pending technology for a "solar forced air furnace". They are very hopeful that this solar heating device will be used in many US homes to reduce the energy costs and replace the use of fossil fuels such as oil and gas with renewable solar energy once it hits the market.

As described by the company, the system is anticipated to provide hot air to heat commercial or residential spaces needing heat during cold weather. The system is designed as a series of glass heat concentration tubes which act as solar heat collectors each containing a copper or other heat conducting core which carries the concentrated heat energy from the sun to a plenum where cool air is exposed to the heat concentrator where heat is transferred from the heat concentrator to the cool air producing warm air for heating purposes. The device will be configured to collect energy from the sun, concentrate it into heat and transfer that heat to a moving air stream which can be circulated into various spaces.

The system should be cheaper to invest in than solar panels.

So who knows - solar furnaces for home use may see a strong increase already in the next few years..?